This disclosure refers to methods of verifying and decoding (i.e., unwrapping), a signatured container file consisting of multiple wrapped files residing on a compact disc or imported from an open network by converting them from a standard text file format to native proprietary type files usable on a proprietary computer system.
In the usage of modern computer systems and networks, the situation arises where systems having one proprietary protocol and data format are connected to systems having different data formats and protocols. Thus in order to provide for systems integration in different networks, it is necessary that there be provided a system or method whereby the data formats of a first system can be transferred to and utilized by the network of a differently oriented system.
For example, the Unisys A Series computer systems involve a Central Processing Unit and memory together with storage such as disk storage which operates under the control of a Master Control Program. These A Series systems use a particular format for the data files compatible with the A Series software which can be placed on CD-ROMs. Thus, the CD-ROMs which contain this A Series software contain an image of a formatted tape which can be utilized only by the A Series systems.
However, when it is desirable to integrate a first system such as the A Series systems for operation with other platforms such as an NT system, then problems arise in that the second system such as the NT system, utilizes formats which are not compatible with the software formats of the A Series system, which is the first system.
Presently, the software for a first system, such as an A Series system with software, is utilized by providing methods to burn CD disks from a Library Maintenance formatted tape. This method has the limitation in that it limits the type of files that are burned into CD-ROMs to those of the native A Series files.
Now, in order to provide for system integration where an A Series system is to be coupled to an NT system, which overall system would be designated as a Unisys ClearPath system, the desirability here would be to make and use a single CD-ROM disk which would carry both the A Series software and at the same time carry the NT software.
Thus in this regard, a method is needed to couple the A Series files with their native attributes and then arrange them in a format capable of being stored on a particular media such as a CD-ROM which will also hold the readable software for the NT system.
The same system or method also provides the ability to package files of a proprietary system in such a way that allows the files to be transported across an open (non-proprietary) network without losing their original characteristics. When such files return to their native environment, their true data formats can be restored by invoking an UNWRAP procedure.
For example, the A Series systems have files with specialized attributes such as FILEXIND, CREATIONDATE, RELEASEID, etc. When these files are transferred to a PC running Windows NT, all those attributes will be lost. By packaging the files and their attributes into standard, simple text files, the new files then can be transported across any open system (e.g., UNIX, NT). Upon reaching their destinations (which are other A Series systems), the text files are converted (UNWRAPPED) back to their native formats with all the proper attributes. This is ideal for maintaining A Series data formats in a heterogeneous networking environment.
A digital signature is calculated for every file as it is being WRAPPED (packaged). This signature is calculated using the Disk File Header (DFH) and the data within the file, along with the Public/Private key pair. This will ensure that there is no intentional corruption of the Disk File Header (DFH) and the data as the file is shipped across a network. It will also provide the receiver of the file a certain measure of confidence as to the origin of the file. Additionally added to the signature, there will be calculated a checksum for entire contents of the file, including the Disk File Header.
When a file is xe2x80x9cwrappedxe2x80x9d with a request for digital signature, its Disk File Header will have a checksum, its entire file will also have another checksum, and a digital signature will be calculated for the entire contents of the newly wrapped file. The functionality of wrapping files with digital signature is available through the WFL (Work Flow Language) syntax as well as through a programmatic interface.
As a result, the Unisys A Series systems will provide a programmatic interface to its Master Control Program (MCP) which will provide a mechanism for wrapping files with signature and for xe2x80x9cunwrappingxe2x80x9d signatured wrapped files.
When a wrapped file is unwrapped, the Unisys A-Series computer determines if a digital signature is present within the file. If so, it will attempt to authenticate the signature to ensure that the data has not been altered. Once the verification process completes successfully, the system permits the file to be re-created into its native form. The Work Flow Language (WFL) syntax will also be provided for this functionality.
xe2x80x9cWrappingxe2x80x9d is a term which is used to define the process of packaging an A Series file, along with its Disk File Header information and a checksum and optionally a digital signature, as a byte-stream data file, so that it can be transported across heterogeneous networks and non-A Series specific media, while still maintaining its native A Series attributes.
xe2x80x9cUnwrappingxe2x80x9d is a term used to define the process of taking a previously xe2x80x9cwrapped filexe2x80x9d and coupling it with the information from its original Disk File Header (DFH) in order to restore the original native A Series file, as it existed prior to being wrapped.
Thus, the problem of a software and file format which is oriented to one specialized system can now be transformed in order to provide a format that is utilizable not just for a first system, but also for a first and second system, whereby the second system would not ordinarily be compatible with the first system. Thus, it is desirable to allow files (created on a Unisys ClearPath HKP/NX system or A-Series system) to be transformed so they can transport across a completely different system (such as NT) without loss of the file""s original native characteristics.
The present disclosure involves signature verification with the xe2x80x9cUnwrapxe2x80x9d operation of a container of multiple files and directories, whereby there are provided methods giving the ability to restore container files that were previously xe2x80x9csignaturedxe2x80x9d and wrapped into text stream data files, and which were transported across an open network or were burned onto industry-standard Compact Disks for distribution.
This method and system for example, provides a Unisys A-Series computer User a measure of confidence when restoring a container of wrapped files from a Compact Disk or from other communication means (for example, MS Mail, Internet, etc.). If the container file""s signature is verified, then the file data is guaranteed from corruption.
A first platform having a specialized proprietary native format for a container of multiple files and/or directories of files of a first platform having a specialized proprietary native format can be put into a single simple byte stream container file usable by a second platform or placed onto an industry standard CD-ROM.
Now, when this byte stream container file is used to communicate with the first platform, the file must be verified through a signature which was attached to it before any of its internal wrapped files can be xe2x80x9cunwrappedxe2x80x9d or re-created back to the proprietary native first format.
Thus, when original specialized and formatted native proprietary container files have been signatured and converted to a byte stream industry-standard data file of a container to be burned on a Compact Disk or transported across an open network, it is often necessary to recapture the original files within the container for use by the proprietary system which has often been integrated with another system, and which may involve a Microsoft Windows NT, a UNIX or other platform in a network integrated with an A-Series system.
The present method and network allows a typical integrated system network, such as a Unisys A-Series and Microsoft NT system, to utilize the byte stream container data files from a Compact Disk (or from the network) and programmatically transform the byte stream data files within the container, after verifying their digital signatures, into their originally specified format and native attributes, usable by the A-Series platform.
The Work Flow Language of a Unisys A Series system utilizes an UNWRAP command allowing the A Series Master Control Program to verify the container""s signature with its MCP_FILEWRAPPER routine which then calls an MCP_WRAPPER routine to reconstitute (unwrap) the container""s signature and unwraps the container of the original native files existing within the container for use by the original proprietary system and its specialized and formatted native files.
The present method of verifying the container signature and unwrapping the container""s files provides security and data integrity to ensure that none of the container""s files are tampered with or altered during transit.